Preservation

I wanted to recover some VHS tapes. Somehow this turned into tapping a signal inside a Sony VCR, putting capture cards in a computer from the junk pile at work, spreading the processing across three machines, and asking Codex to help redesign an amplifier PCB.

There is a reason I went this way. The usual way to digitize VHS is to connect a VCR’s video and audio outputs to a capture device and record them on a computer. The VCR reads the tape and turns its signal into a picture before the computer ever sees it.

For better results, you can look for a nicer VCR with a built-in time base corrector, or TBC, which helps correct playback timing errors that make the picture wobble. Unfortunately, the decks I was looking at were $$$. With ancient media having a moment again, it feels like everybody wants the same aging hardware. The expensive stuff is, well, expensive.

VHS-Decode offers a more hardcore route. You still need a working VCR, but you tap the RF signal inside it, near the tape-head amplifier, before the machine turns it into ordinary video. This is not the antenna connector on the back. Suitable capture hardware records that earlier signal, and the computer reconstructs the picture, including time base correction, in software.